Few persons care to study logic, because everybody conceives himself to be proficient
enough in the art of reasoning already. But I observe that this satisfaction is limited to
one's own ratiocination, and does not extend to that of other men.

We come to the full possession of our power of drawing inferences, the last of all our
faculties; for it is not so much a natural gift as a long and difficult art. The history
of its practice would make a grand subject for a book. The medieval schoolmen, following
the Romans, made logic the earliest of a boy's studies after grammar, as being very easy.
So it was as they understood it. Its fundamental principle, according to them, was, that
all knowledge rests either on authority or reason; but that whatever is deduced by reason
depends ultimately on a premiss derived from authority. Accordingly, as soon as a boy was
perfect in the syllogistic procedure, his intellectual kit of tools was held to be
complete.

To Roger Bacon, that remarkable mind who in the middle of the thirteenth century was
almost a scientific man, the schoolman's conception of reasoning appeared only an obstacle
to truth. He saw that experience alone teaches anythinga proposition which to us
seems easy to understand, because a distinct conception of experience has been handed down
to us from former generations; which to him likewise seemed perfectly clear, because its
difficulties had not yet unfolded themselves. Of all kinds of experience, the best, he
thought, was interior illumination, which teaches many things about Nature which the
external senses could never discover, such as the transubstantiation of bread.

Four centuries later, the more celebrated Bacon, in the first book of his Novum
Organum, gave his clear account of experience as something which must be open to
verification and reŽxamination. But, superior as Lord Bacon's conception is to earlier
notions, a modern reader who is not in awe of his grandiloquence is chiefly struck by the
inadequacy of his view of scientific procedure. That we have only to
make some crude experiments, to draw up briefs of the results in certain blank forms, to
go through these by rule, checking off everything disproved and setting down the
alternatives, and that thus in a few years physical science would be finished upwhat
an idea! "He wrote on science like a Lord Chancellor," indeed, as Harvey, a
genuine man of science said.

The early scientists, Copernicus, Tycho Brahe, Kepler, Galileo, Harvey, and Gilbert had
methods more like those of their modern brethren. Kepler undertook to draw a curve through
the places of Mars, and to state the times occupied by the planet in describing the
different parts of that curve; but perhaps his greatest service to science was in
impressing on men's minds that this was the thing to be done if they wished to improve
astronomy; that they were not to content themselves with inquiring whether one system of
epicycles was better than another, but that they were to sit down to the figures and find
out what the curve, in truth, was. He accomplished this by his incomparable energy and
courage, blundering along in the most inconceivable ways (to us), from one irrational
hypothesis to another, until, after trying twenty-two of these, he fell, by the mere
exhaustion of his invention, upon the orbit which a mind well furnished with the weapons
of modern logic would have tried almost at the outset.1

In the same way, every work of science great enough to be well remembered for a few
generations affords some exemplification of the defective state of the art of reasoning of
the time when it was written, and each chief step in science has been a lesson in logic.
It was so when Lavoisier and his contemporaries took up the study of Chemistry. The old
chemist's maxim had been, "Lege, lege, lege, labora, ora, et relege."
Lavoisier's method was not to read and pray, not2 to dream
that some long and complicated chemical process would have a certain effect, to put it
into practice with dull patience, after its inevitable failure, to dream that with some
modification it would have another result, and to end by publishing the last dream as a
fact: his way was to carry his mind into his laboratory, and literally to make of his
alembics and cucurbits instruments of thought, giving a new conception of reasoning as
something which was to be done with one's eyes open, in manipulating real things instead
of words and fancies.

The Darwinian controversy is, in large part, a question of logic. Mr. Darwin proposed
to apply the statistical method to biology. The same thing has been done in a widely
different branch of science, the theory of gases. Though unable to say what the movements
of any particular molecule would be on a certain hypothesis regarding the constitution of
this class of bodies, Clausius and Maxwell were yet able, eight years before the
publication of Darwin's immortal work, by the application of the doctrine of
probabilities, to predict that in the long run such and such a proportion of the molecules
would, under given circumstances, acquire such and such velocities; that there would take
place, every second, such and such a relative number of collisions, etc.; and from these
propositions were able to deduce certain properties of gases, especially in regard to
their heat-relations. In like manner, Darwin, while unable to say what the operation of
variation and natural selection in any individual case will be, demonstrates that in the
long run they will, or would, adapt animals to their circumstances. Whether or not
existing animal forms are due to such action, or what position the theory ought to take,
forms the subject of a discussion in which questions of fact and questions of logic are
curiously interlaced.

The object of reasoning is to find out, from the consideration of what we already know,
something else which we do not know. Consequently, reasoning is good if it be such as to
give a true conclusion from true premises, and not otherwise. Thus, the question of
validity is purely one of fact and not of thinking. A being the facts stated in the
premisses and B being that concluded, the question is, whether these facts are really so
related that if A were B would generally be. If so, the inference is valid; if not, not.
It is not in the least the question whether, when the premisses are accepted by the mind,
we feel an impulse to accept the conclusion also. It is true that we do generally reason
correctly by nature. But that is an accident; the true conclusion would remain true if we
had no impulse to accept it; and the false one would remain false, though we could not
resist the tendency to believe in it.

We are, doubtless, in the main logical animals, but we are not perfectly so. Most of
us, for example, are naturally more sanguine and hopeful than logic would justify. We seem
to be so constituted that in the absence of any facts to go upon we are happy and
self-satisfied; so that the effect of experience is continually to contract our hopes and
aspirations. Yet a lifetime of the application of this corrective does not usually
eradicate our sanguine disposition. Where hope is unchecked by any experience, it is
likely that our optimism is extravagant. Logicality in regard to practical matters (if
this be understood, not in the old sense, but as consisting in a wise union of security
with fruitfulness of reasoning) is the most useful quality an animal can possess, and
might, therefore, result from the action of natural selection; but outside of these it is
probably of more advantage to the animal to have his mind filled with pleasing and
encouraging visions, independently of their truth; and thus, upon unpractical subjects,
natural selection might occasion a fallacious tendency of thought.

That which determines us, from given premisses, to draw one inference rather than
another, is some habit of mind, whether it be constitutional or acquired. The habit is
good or otherwise, according as it produces true conclusions from true premises or not;
and an inference is regarded as valid or not, without reference to the truth or falsity of
its conclusion specially, but according as the habit which determines it is such as to
produce true conclusions in general or not. The particular habit of mind which governs
this or that inference may be formulated in a proposition whose truth depends on the
validity of the inferences which the habit determines; and such a formula is called a guiding
principle of inference. Suppose, for example, that we observe that a rotating disk of
copper quickly comes to rest when placed between the poles of a magnet, and we infer that
this will happen with every disk of copper. The guiding principle is, that what is true of
one piece of copper is true of another. Such a guiding principle with regard to copper
would be much safer than with regard to many other substancesbrass, for example.

A book might be written to signalize all the most important of these guiding principles
of reasoning. It would probably be, we must confess, of no service to a person whose
thought is directed wholly to practical subjects, and whose activity moves along
thoroughly-beaten paths. The problems that present themselves to such a mind are matters
of routine which he has learned once for all to handle in learning his business. But let a
man venture into an unfamiliar field, or where his results are not continually checked by
experience, and all history shows that the most masculine intellect3
will ofttimes lose his orientation and waste his efforts in directions which bring him no
nearer his goal, or even carry him entirely astray. He is like a ship in the open sea,
with no one on board who understands the rules of navigation. And in such a case some
general study of the guiding principles of reasoning would be sure to be found useful.

The subject could hardly be treated, however, without being first limited; since almost
any fact may serve as a guiding principle. But it so happens that there exists a division
among facts, such that in one class are all those which are absolutely essential as
guiding principles, while in the other are all which have any other interest as objects of
research. This division is between those which are necessarily taken for granted in asking
why a certain conclusion is thought to follow from certain premisses, and those which are
not implied in such a question. A moment's thought will show that a variety of facts are
already assumed when the logical question is first asked. It is implied, for instance,
that there are such states of mind as doubt and beliefthat a passage from one to the
other is possible, the object of thought remaining the same, and that this transition is
subject to some rules by which all minds are alike bound. As these are facts which we must
already know before we can have any clear conception of reasoning at all, it cannot be
supposed to be any longer of much interest to inquire into their truth or falsity. On the
other hand, it is easy to believe that those rules of reasoning which are deduced from the
very idea of the process are tho ones which are the most essential; and, indeed, that so
long as it conforms to these it will, at least, not lead to false conclusions from true
premisses. In point of fact, the importance of what may be deduced from the assumptions
involved in the logical question turns out to be greater than might be supposed, and this
for reasons which it is difficult to exhibit at the outset. The only one which I shall
here mention is, that conceptions which are really products of logical reflection, without
being readily seen to be so, mingle with our ordinary thoughts, and are frequently the
causes of great confusion. This is the case, for example, with the conception of quality.
A quality, as such, is never an object of observation. We can see that a thing is blue or
green, but the quality of being blue and the quality of being green are not things which
we see; they are products of logical reflections. The truth is, that common-sense, or
thought as it first emerges above the level of the narrowly practical, is deeply imbued
with that bad logical quality to which the epithet metaphysical is commonly
applied; and nothing can clear it up but a severe course of logic.

We generally know when we wish to ask a question and when we wish to pronounce a
judgment, for there is a dissimilarity between the sensation of doubting and that of
believing.

But this is not all which distinguishes doubt from belief. There is a practical
difference. Our beliefs guide our desires and shape our actions. The Assassins, or
followers of the Old Man of the Mountain, used to rush into death at his least command,
because they believed that obedience to him would insure everlasting felicity. Had they
doubted this, they would not have acted as they did. So is it with every belief, according
to its degree. The feeling of believing is a more or less sure indication of there being
established in our nature some habit which will determine our actions. Doubt never has
such an effect.

Nor must we overlook a third point of difference. Doubt is an uneasy and dissatisfied
state from which we struggle to free ourselves. and pass into the state of belief; while
the latter is a calm and satisfactory state which we do not wish to avoid, or to change to
a belief in anything else. On the contrary, we cling tenaciously, not merely to believing,
but to believing just what we do believe.

Thus, both doubt and belief have positive effects upon us, though very different ones.
Belief does not make us act at once, but puts us into such a condition that we shall
behave in some certain way, when the occasion arises. Doubt has not the least such active
effect, but stimulates us to inquiry until it is destroyed. This reminds us of the
irritation of a nerve and the reflex action produced thereby; while for the analogue of
belief, in the nervous system, we must look to what are called nervous
associationsfor example, to that habit of the nerves in consequence of which the
smell of a peach will make the mouth water.

The irritation of doubt causes a struggle to attain a state of belief. I shall term
this struggle Inquiry, though it must be admitted that this is sometimes not a very
apt designation.

The irritation of doubt is the only immediate motive for the struggle to attain belief.
It is certainly best for us that our beliefs should be such as may truly guide our actions
so as to satisfy our desires; and this reflection will make us reject every belief which
does not seem to have been so formed as to insure this result. But it will only do so by
creating a doubt in place of that belief. With the doubt, therefore, the struggle begins,
and with the cessation of doubt it ends. Hence, the sole object of inquiry is the
settlement of opinion. We may fancy that this is not enough for us, and that we seek, not
merely an opinion, but a true opinion. But put this fancy to the test, and it proves
groundless; for as soon as a firm belief is reached we are entirely satisfied, whether the
belief be true or false. And it is clear that nothing out of the sphere of our knowledge
can be our object, for nothing which does not affect the mind can be the motive for mental
effort. The most that can be maintained is, that we seek for a belief that we shall think
to be true. But we think each one of our beliefs to be true, and, indeed, it is mere
tautology to say so.

That the settlement of opinion is the sole end of inquiry is a very important
proposition. It sweeps away, at once, various vague and erroneous conceptions of proof. A
few of these may be noticed here.

1. Some philosophers have imagined that to start an inquiry it was only necessary to
utter a question whether orally or by setting it down upon paper, and have even
recommended us to begin our studies with questioning everything! But the mere putting of a
question into the interrogative form does not stimulate the mind to any struggle after
belief. There must be a real and living doubt, and without this all discussion is idle.

2. It is a very common idea that a demonstration must rest on some ultimate and
absolutely indubitable propositions. These, according to one school, are first principles
of a general nature; according to another, are first sensations. But, in point of fact, an
inquiry, to have that completely satisfactory result called demonstration, has only to
start with propositions perfectly free from all actual doubt. If the premises are not in
fact doubted at all, they cannot be more satisfactory than they are.

3. Some people seem to love to argue a point after all the world is fully convinced of
it. But no further advance can be made. When doubt ceases, mental action on the subject
comes to an end; and, if it did go on, it would be without a purpose.

If the settlement of opinion is the sole object of inquiry, and if belief is of the
nature of a habit, why should we not attain the desired end, by taking as answer to a
question any we may fancy, and constantly reiterating it, dwelling on all which may
conduce to that belief, and learning to turn with contempt and hatred from anything that
might disturb it? This simple and direct method is really pursued by many men. I remember
once being entreated not to read a certain newspaper lest it might change my opinion upon
free-trade. "Lest I might be entrapped by its fallacies and misstatements," was
the form of expression. "You are not," my friend said, "a special student
of political economy. You might, therefore, easily be deceived by fallacious arguments
upon the subject. You might, then, if you read this paper, be led to believe in
protection. But you admit that free-trade is the true doctrine; and you do not wish to
believe what is not true." I have often known this system to be deliberately adopted.
Still oftener, the instinctive dislike of an undecided state of mind, exaggerated into a
vague dread of doubt, makes men cling spasmodically to the views they already take. The
man feels that, if he only holds to his belief without wavering, it will be entirely
satisfactory. Nor can it be denied that a steady and immovable faith yields great peace of
mind. It may, indeed, give rise to inconveniences, as if a man should resolutely continue
to believe that fire would not burn him, or that he would be eternally damned if he
received his ingesta otherwise than through a stomach-pump. But then the man who
adopts this method will not allow that its inconveniences are greater than its advantages.
He will say, "I hold steadfastly to the truth, and the truth is always
wholesome." And in many cases it may very well be that the pleasure he derives from
his calm faith overbalances any inconveniences resulting from its deceptive character.
Thus, if it be true that death is annihilation, then the man who believes that he will
certainly go straight to heaven when he dies, provided he have fulfilled certain simple
observances in this life, has a cheap pleasure which will not be followed by the least
disappointment. A similar consideration seems to have weight with many persons in
religious topics, for we frequently hear it said, "Oh, I could not believe so-and-so,
because I should be wretched if I did." When an ostrich buries its head in the sand
as danger approaches, it very likely takes the happiest course. It hides the danger, and
then calmly says there is no danger; and, if it feels perfectly sure there is none, why
should it raise its head to see? A man may go through life, systematically keeping out of
view all that might cause a change in his opinions, and if he only succeedsbasing
his method, as he does, on two fundamental psychological lawsI do not see what can
be said against his doing so. It would be an egotistical impertinence to object that his
procedure is irrational, for that only amounts to saying that his method of settling
belief is not ours. He does not propose to himself to be rational, and, indeed, will often
talk with scorn of man's weak and illusive reason. So let him think as he pleases.

But this method of fixing belief, which may be called the method of tenacity, will be
unable to hold its ground in practice. The social impulse is against it. The man who
adopts it will find that other men think differently from him, and it will be apt to occur
to him, in some saner moment, that their opinions are quite as good as his own, and this
will shake his confidence in his belief. This conception, that another man's thought may
be equivalent to one's own, is a distinctly new step, and a highly important one. It
arises from an impulse too strong in man to be suppressed, without danger of destroying
the human species. Unless we make ourselves hermits, we shall necessarily influence each
other's opinions; so that the problem becomes how to fix belief, not in the individual
merely, but in the community.

Let the will of the state act, then, instead of that of the individual. Let an
institution be created which shall have for its object to keep correct doctrines before
the attention of the people, to reiterate them perpetually, and to teach them to the
young; having at the same time power to prevent contrary doctrines from being taught,
advocated, or expressed. Let all possible causes of a change of mind be removed from men's
apprehensions. Let them be kept ignorant, lest they should learn of some reason to think
otherwise than they do. Let their passions be enlisted, so that they may regard private
and unusual opinions with hatred and horror. Then, let all men who reject the established
belief be terrified into silence. Let the people turn out and tar-and-feather such men, or
let inquisitions be made into the manner of thinking of suspected persons, and when they
are found guilty of forbidden beliefs, let them be subjected to some signal punishment.
When complete agreement could not otherwise be reached, a general massacre of all who have
not thought in a certain way has proved a very effective means of settling opinion in a
country. If the power to do this be wanting, let a list of opinions be drawn up, to which
no man of the least independence of thought can assent, and let the faithful be required
to accept all these propositions, in order to segregate them as radically as possible from
the rest of the world.

This method has, from the earliest times, been one of the chief means of upholding
correct theological and political doctrines, and of preserving their universal or catholic
character. In Rome, especially, it has been practiced from the days of Numa Pompilius to
those of Pius Nonus. This is the most perfect example in history; but wherever there is a
priesthoodand no religion has been without onethis method has been more or
less made use of. Wherever there is an aristocracy, or a guild, or any association of a
class of men whose interests depend, or are supposed to depend, on certain propositions,
there will be inevitably found some traces of this natural product of social feeling.
Cruelties always accompany this system; and when it is consistently carried out, they
become atrocities of the most horrible kind in the eyes of any rational man. Nor should
this occasion surprise, for the officer of a society does not feel justified in
surrendering the interests of that society for the sake of mercy, as he might his own
private interests. It is natural, therefore, that sympathy and fellowship should thus
produce a most ruthless power.

In judging this method of fixing belief, which may be called the method of authority,
we must, in the first place, allow its immeasurable mental and moral superiority to the
method of tenacity. Its success is proportionately greater; and, in fact, it has over and
over again worked the most majestic results. The main structures of stone which it has
caused to be put togetherin Siam, for example, in Egypt, and in Europehave
many of them sublimity hardly more than rivaled by the greatest works of Nature. And,
except the geological epochs, there are no periods of time so vast as those which are
measured by some of these organized faiths. If we scrutinize the matter closely, we shall
find that there has not been one of their creeds which has remained always the same; yet
the change is so slow as to be imperceptible during one person's life, so that individual
belief remains sensibly fixed. For the mass of mankind, then, there is perhaps no better
method than this. If it is their highest impulse to be intellectual slaves, then slaves
they ought to remain.

But no institution can undertake to regulate opinions upon every subject. Only the most
important ones can be attended to, and on the rest men's minds must be left to the action
of natural causes. This imperfection will be no source of weakness so long as men are in
such a state of culture that one opinion does not influence anotherthat is, so long
as they cannot put two and two together. But in the most priest-ridden states some
individuals will be found who are raised above that condition. These men possess a wider
sort of social feeling; they see that men in other countries and in other ages have held
to very different doctrines from those which they themselves have been brought up to
believe; and they cannot help seeing that it is the mere accident of their having been
taught as they have, that has caused them to believe as they do and not differently. Nor
can their candour resist the reflection that there is no reason to rate their own views at
a higher value than those of other nations and other centuries; thus giving rise to doubts
in their minds.

They will further perceive that such doubts as these must exist in their minds with
reference to every belief which seems to be determined by the caprice either of themselves
or of those who originated the popular opinions. The willful adherence to a belief, and
the arbitrary forcing of it upon others, must, therefore, both be given up. A different
new method of settling opinions must be adopted, that shall not only produce an impulse to
believe, but shall also decide what proposition it is which is to be believed. Let the
action of natural preferences be unimpeded, then, and under their influence let men,
conversing together and regarding matters in different lights, gradually develop beliefs
in harmony with natural causes. This method resembles that by which conceptions of art
have been brought to maturity. The most perfect example of it is to be found in the
history of metaphysical philosophy. Systems of this sort have not usually rested upon any
observed facts, at least not in any great degree. They have been chiefly adopted because
their fundamental propositions seemed "agreeable to reason." This is an apt
expression; it does not mean that which agrees with experience, but that which we find
ourselves inclined to believe. Plato, for example, finds it agreeable to reason that the
distances of the celestial spheres from one another should be proportional to the
different lengths of strings which produce harmonious chords. Many philosophers have been
led to their main conclusions by considerations like this; but this is the lowest and
least developed form which the method takes, for it is clear that another man might find
Kepler's theory, that the celestial spheres are proportional to the inscribed and
circumscribed spheres of the different regular solids, more agreeable to his
reason. But the shock of opinions will soon lead men to rest on preferences of a far more
universal nature. Take, for example, the doctrine that man only acts selfishlythat
is, from the consideration that acting in one way will afford him more pleasure than
acting in another. This rests on no fact in the world, but it has had a wide acceptance as
being the only reasonable theory.

This method is far more intellectual and respectable from the point of view of reason
than either of the others which we have noticed. Indeed, as long as no better method can
be applied, it ought to be followed, since it is then the expression of instinct which
must be the ultimate cause of belief in all cases. But its failure has been the most
manifest. It makes of inquiry something similar to the development of taste; but taste,
unfortunately, is always more or less a matter of fashion, and accordingly metaphysicians
have never come to any fixed agreement, but the pendulum has swung backward and forward
between a more material ad a more spiritual philosophy, from the earliest times to the
latest. And so from this, which has been called the a priori method, we are driven,
in Lord Bacon's phrase, to a true induction. We have examined into this a priori
method as something which promised to deliver our opinions from their accidental and
capricious element. But development, while it is process which eliminates the effect of
some casual circumstances, only magnifies that of others. This method, therefore, does not
differ in a very essential way from that of authority. The government may not have lifted
its finger to influence my convictions; I may have been left outwardly quite free to
choose, we will say, between monogamy and polygamy, and, appealing to my conscience only,
I may have concluded that the latter practice is in itself licentious. But when I see that
the chief obstacle to the spread of Christianity among a people of as high culture as the
Hindoos has been a conviction of the immorality of our way of treating women, I cannot
help seeing that, though governments do not interfere, sentiments in their development
will be very greatly determined by accidental causes. Now, there are some people, among
whom I must suppose that my reader is to be found, who, when they see that any belief of
theirs is determined by any circumstance extraneous to the facts, will from that moment
not merely admit in words that that belief is doubtful, but experience a real doubt of it,
so that it ceases in some degree at least to be a belief.

To satisfy our doubts, therefore, it is necessary that a method should by found by
which our beliefs may be determined by nothing human, but by some external
permanencyby something upon which our thinking has no effect. Some mystics imagine
that they have such a method in a private inspiration from on high. But that is only a
form of the method of tenacity, in which the conception of truth as something public is
not yet developed. Our external permanency would not be external, in our sense, if it was
restricted in its influence to one individual. It must be something which affects, or
might affect, every man. And, though these affections are necessarily as various as are
individual conditions, yet the method must be such that the ultimate conclusion of every
man shall be the same. Such is the method of science. Its fundamental hypothesis, restated
in more familiar language, is this: There are Real things, whose characters are entirely
independent of our opinions about them; those Reals affect our senses according to regular
laws, and, though our sensations are as different as are our relations to the objects,
yet, by taking advantage of the laws of perception, we can ascertain by reasoning how
things really and truly are; and any man, if he have sufficient experience and he reason
enough about it, will be led to the one True conclusion. The new conception here involved
is that of Reality. It may be asked how I know that there are any Reals. If this
hypothesis is the sole support of my method of inquiry, my method of inquiry must not be
used to support my hypothesis. The reply is this: 1. If investigation cannot be regarded
as proving that there are Real things, it at least does not lead to a contrary conclusion;
but the method and the conception on which it is based remain ever in harmony. No doubts
of the method, therefore, necessarily arise from its practice, as is the case with all the
others. 2. The feeling which gives rise to any method of fixing belief is a
dissatisfaction at two repugnant propositions. But here already is a vague concession that
there is some one thing which a proposition should represent. Nobody, therefore,
can really doubt that there are Reals, for, if he did, doubt would not be a source of
dissatisfaction. The hypothesis, therefore, is one which every mind admits. So that the
social impulse does not cause men to doubt it. 3. Everybody uses the scientific method
about a great many things, and only ceases to use it when he does not know how to apply
it. 4. Experience of the method has not led us to doubt it, but, on the contrary,
scientific investigation has had the most wonderful triumphs in the way of settling
opinion. These afford the explanation of my not doubting the method or the hypothesis
which it supposes; and not having any doubt, nor believing that anybody else whom I could
influence has, it would be there merest babble for me to say more about it. If there be
anybody with a living doubt upon the subject, let him consider it.

To describe the method of scientific investigation is the object of this series of
papers. At present I have only room to notice some points of contrast between it and other
methods of fixing belief.

This is the only one of the four methods which presents any distinction of a right and
a wrong way. If I adopt the method of tenacity, and shut myself out from all influences,
whatever I think necessary to doing this, is necessary according to that method. So with
the method of authority: the state may try to put down heresy by means which, from a
scientific point of view, seem very ill-calculated to accomplish its purposes; but the
only test on that method is what the state thinks; so that it cannot pursue the
method wrongly. So with the a priori method. The very essence of it is to think as
one is inclined to think. All metaphysicians will be sure to do that, however they may be
inclined to judge each other to be perversely wrong. The Hegelean system recognizes every
natural tendency of thought as logical, although it be certain to be abolished by
counter-tendencies. Hegel thinks there is a regular system in the succession of these
tendencies, in consequence of which, after drifting one way and the other for a long time,
opinion will at last go right. And it is true that metaphysicians do get the right ideas
at last; Hegel's system of Nature represents tolerably the science of his day; and one may
be sure that whatever scientific investigation shall have put out of doubt will presently
receive a priori demonstration on the part of the metaphysicians. But with the
scientific method the case is different. I may start with known and observed facts to
proceed to the unknown; and yet the rules which I follow in doing so may not be such as
investigation would approve. The test of whether I am truly following the method is not an
immediate appeal to my feelings and purposes, but, on the contrary, itself involves the
application of the method. Hence it is that bad reasoning as well as good reasoning is
possible; and this fact is the foundation of the practical side of logic.

It is not to be supposed that the first three methods of settling opinion present no
advantage whatever over the scientific method. On the contrary, each has some peculiar
convenience of its own. The a priori method is distinguished for its comfortable
conclusions. It is the nature of the process to adopt whatever belief we are inclined to,
and there are certain flatteries to the vanity of man which we all believe by nature,
until we are awakened from our pleasing dream by rough facts. The method of authority will
always govern the mass of mankind; and those who wield the various forms of organized
force in the state will never be convinced that dangerous reasoning ought not to be
suppressed in some way. If liberty of speech is to be untrammelled from the grosser forms
of constraint, then uniformity of opinion will be secured by a moral terrorism to which
the respectability of society will give its thorough approval. Following the method of
authority is the path of peace. Certain non-conformities are permitted; certain others
(considered unsafe) are forbidden. These are different in different countries and in
different ages; but, wherever you are, let it be known that you seriously hold a tabooed
belief, and you may be perfectly sure of being treated with a cruelty less brutal but more
refined than hunting you like a wolf. Thus, the greatest intellectual benefactors of
mankind have never dared, and dare not now, to utter the whole of their thought; and thus
a shade of prima facie doubt is cast upon every proposition which is considered
essential to the security of society. Singularly enough, the persecution does not all come
from without; but a man torments himself and is oftentimes most distressed at finding
himself believing propositions which he has been brought up to regard with aversion. The
peaceful and sympathetic man will, therefore, find it hard to resist the temptation to
submit his opinions to authority. But most of all I admire the method of tenacity for its
strength, simplicity, and directness. Men who pursue it are distinguished for their
decision of character, which becomes very easy with such a mental rule. They do not waste
time in trying to make up their minds what they want, but, fastening like lightening upon
whatever alternative comes first, they hold it to the end, whatever happens, without an
instant's irresolution. This is one of the splendid qualities which generally accompany
brilliant, unlasting success. It is impossible not to envy the man who can dismiss reason,
although we know how it must turn out at last.

Such are the advantages which the other methods of settling opinion have over
scientific investigation. A man should consider well of them; and then he should consider
that, after all, he wishes his opinions to coincide with fact, and that there is no reason
why the results of those three first methods should do so. To bring about this effect is
the prerogative of the method of science. Upon such considerations he has to make his
choice--a choice which is far more than the adoption of any intellectual opinion, which is
one of the ruling decisions of his life, to which, when once made, he is bound to adhere.
The force of habit will sometimes cause a man to hold on to old beliefs, after he is in a
condition to see that they have no sound basis. But reflection upon the state of the case
will overcome these habits, and he ought to allow reflection its full weight. People
sometimes shrink from doing this, having an idea that beliefs are wholesome which they
cannot help feeling rest on nothing. But let such persons suppose an analogous though
different case from their own. Let them ask themselves what they would say to a reformed
Mussulman who should hesitate to give up his old notions in regard to the relations of the
sexes; or to a reformed Catholic who should still shrink from reading the Bible. Would
they not say that these persons ought to consider the matter fully, and clearly understand
the new doctrine, and then ought to embrace it, in its entirety? But above all, let it be
considered that what is more wholesome than any particular belief is integrity of belief,
and that to avoid looking into the support of any belief from a fear that it may turn out
rotten is quite as immoral as it is disadvantageous. The person who confesses that there
is such a thing as truth, which is distinguished from falsehood simply by this, that if
acted on it should, on full consideration, carry us to the point we aim at and not astray,
and then, though convinced of this, dares not know the truth and seeks to avoid it, is in
a sorry state of mind indeed.

Yes, the other methods do have their merits: a clear logical conscience does cost
somethingjust as any virtue, just as all that we cherish, costs us dear. But we
should not desire it to be otherwise. The genius of a man's logical method should be loved
and reverenced as his bride, whom he has chosen from all the world. He need not contemn
the others; on the contrary, he may honour them deeply, and in doing so he only honours
her the more. But she is the one that he has chosen, and he knows that he was right in
making that choice. And having made it, he will work and fight for her, and will not
complain that there are blows to take, hoping that there may be as many and hard to give,
and will strive to be the worthy knight and champion of her from the blaze of whose
splendors he draws his inspiration and his courage.

Notes

1. I am ashamed at being obliged to confess that this volume contains
a very false and foolish remark about Kepler. When I wrote it, I had never studied the
original book as I have since. It is now my deliberate opinion that it is the most
marvelous piece of inductive reasoning I have been able to find1893 (csp).

2. Most versions of this paper have "but" here in place of
"not"; however, see Marcus G. Singer, "Not But